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Lees weergave

Antoine BeauprΓ©: PSA: Europe changes time forward soon, North America next, for the last time?

This is a copy of an email I sent at work. I'm not sure I should be making noise about this here, feedback welcome.

This is your bi-yearly reminder that time is changing soon! October 25th in Europe, November 1st in North America. Less people in Canada are changing this year, with BC, Alberta, Manitoba and Northwest Territories getting rid of DST.

What's happening?

Some places in the world implement what is called Daylight saving time or DST:

https://en.wikipedia.org/wiki/Daylight_saving_time

Normally, you shouldn't have to do anything: computers automatically change time following local rules, assuming they are correctly configured, provided recent updates have been applied in the case of a recent change in said rules (because yes, this happens, and happened this year, and yes, you need to upgrade your software!).

Of course, appliances like your microwave oven will likely not change time and will need to adjusted unless they are so-called "smart", in which case they are part of the skynet botnet and should be destroyed.

If your clock is flashing "0:00" or "12:00", you have no action to take to adapt to this change, lucky you.

If you haven't changed time in six months, congratulations, your clock will be accurate again!

In any case, you should still consider DST because it might affect some of your meeting schedules, particularly if you set up a new meeting schedule in the last 6 months and forgot to consider this change.

If your location does not have DST

Properly scheduled meetings affecting multiple time zones are set in UTC time, which does not change. So if your location does not observer time changes, your (local!) meeting time will not change.

But be aware that some other folks attending your meeting might have the DST bug and their meeting times will change.

Be kind to those poor souls which might be missing meetings by a full hour because time flies backwards for them.

If you do observe DST

If you are affected by daylight savings, your local meeting times will change for UTC meetings. Normally, your meeting times are scheduled to take this into account and the new hours should be reasonable.

But now is a good time to verify that. Take a look at your schedule for the next couple of weeks and reschedule meetings before the daylight saving come up to avoid too much disruption. You have only a couple of weeks to do so right now.

When do times change, how, and and where?

As regular readers will remember, the rule of thumb is:

Spring forward, fall backwards.

That is, during the season of Spring, the clocks move forward, and during the Fall (like right now), they move backwards. That is in the northern hemisphere, but then the southern hemisphere is often saner and doesn't switch anyways.

So time will move backwards which means an extra hour of sleep. Unless you have children or bad sleep, in which case your body doesn't care about what the clock says and will wake up one hour earlier than what it should.

And of course, this doesn't happen everywhere at once, so let's see when it happens where.

Europe

The dance starts in Europe.

The change happens on the last Sunday in October at 01:00 UTC (not local time!), that is October 25th. If you are in the central European timezone, also known as Amsterdam, Berlin, or Paris time depending on your national affiliation, that essentially means that at 2:59 local the clocks will fall back to 2:00 instead of going to 3:00.

Concretely, set your watch back one hour before going to bed, go to bed at the normal time, and enjoy an extra hour of sleep or leisure.

If you have kids, you might want to start getting them to bed slightly earlier every day for a week before the change so they take time getting used to the change. If you have trouble sleeping in the morning, find your inner child and do that to yourself as well.

USA / Canada

Then it's the US[1] and Canada[2] joining the dance, on the First Sunday in November at 02:00 local (not UTC!), that is, I believe, November 1st 2026.

This means that, at 1:59, the clocks will flip to 1:00, instead of 2:00.

Concretely, do like the Europeans and tweak your clock before going to bed.

That is a little less than four weeks from now.

[1] except Arizona (except the Navajo nation), US territories, and Hawaii

[2] except Yukon, Saskatchewan, (newly) British Columbia, (newly) Alberta, (newly) Northwest Territories, (newly) Manitoba, one island in Nunavut (Southampton Island), one town in Ontario (Atikokan) and small parts of Quebec (Le Golfe-du-Saint-Laurent)

Other places with DST

This time again, I must apologize to the people of Cuba, Lebanon, Israel, Palestine, Egypt, Chile, Australia, and New Zealand, as you fine folks all have your own DST rules that are omitted here for brevity. I rely on this page from Wikipedia to be updated by time nerds accurately for this message, and it should provide you with a rough idea of what's coming:

https://en.wikipedia.org/wiki/Daylight_saving_time_by_country

In general, changes also happen in October, but either on different times or different days, except in the south hemisphere, where they might happen in September (oops, sorry NZ folks, I'm late!).

Places without DST

Everyone else, enjoy, you're on the right side of history, and we thank you for the good example you give us.

Changes since last time

There's been lots of changes since last time:

  • British Columbia moved to permanent -07 on 2026-03-09, that is it will not change to normal time in November

  • Alberta moved to permanent -06 on 2026-06-18, similar to BC above.

  • Canada’s Northwest Territories moved to permanent -06 on 2026-08-21, matching Alberta.

  • Manitoba moves to permanent -05 on 2026-10-31.

  • Morocco moves to permanent +00 on 2026-09-20.

  • Moldova has used EU transition times since 2022, but the tz database only noticed in 2026

This is my interpretation of the changes announced on the tzdata mailing list here:

https://lists.iana.org/hyperkitty/list/tz-announce@iana.org/latest

If the eastward trend continues, Canada should adopt country-wide "no daylight savings" rules by 2027, although there's actually no sign of the other provinces (Ontario, QuΓ©bec and so on) currently running bills to change those rules just yet. Poor Canadians like me confused about time in their countries can refer to this section of Wikipedia for details:

https://en.wikipedia.org/wiki/Daylight_saving_time_in_Canada#By_province_and_territory

... and particularly the image featured there:

https://commons.wikimedia.org/wiki/File:Canada_time_zone_map-en.svg

It also seems like the US government might finally adopt a permanent daylight saving change bill in 2026, as the "Sunshine protection act" pass the house in July:

https://en.wikipedia.org/wiki/Sunshine_Protection_Act

True to form, this was associated with absolutely ridiculous pressure from Donald Trump against republicans (his own party!) objecting to the change:

On July 14, 2026, the House passed a Sunshine Protection Act bill backed by President Trump. Nevertheless, the bill was opposed in the Senate by Republicans, including Senator Cotton. In response, on October 3, 2026, Trump shared a post on Truth Social urging Cotton to approve the bill, where he revealed Cotton's personal cellphone number and called on people to call him.

https://www.theguardian.com/us-news/2026/oct/03/trump-tom-cotton-daylight-saving-time

Given that the last time the US did a major change to the daylight savings policy (in 2005), Canada followed suit to stay in sync, it's quite possible Trump's mad dash might actually finish getting rid of DST in North America:

https://en.wikipedia.org/wiki/Energy_Policy_Act_of_2005#Change_to_daylight_saving_time

  •  

Steinar H. Gunderson: Decompilation patterns, part 5: Nested if/goto

Here's a pattern that sometimes comes up:

if (x == 3) {
    if (y == 4) {
        ...
    } else {
        goto label_5;
    }
} else {
    label_5:
    ...
}

We don't like gotos, and here, it's pretty obvious what was meant, namely:

if (x == 3 && y == 4) {
    ...
} else {
    label_5:
    ...
}

And now you can usually delete label_5 because nothing points to it.

Often, m2c can do this by itself, but as usual, you may get to this point only after cleaning up other things.

  •  

Thorsten Alteholz: My Debian Activities in September 2026

Debian LTS/ELTS

This was my hundred-forty-seventh month that I did some work for the Debian LTS initiative, started by Raphael Hertzog at Freexian.

During my allocated time I uploaded or worked on:

  • [DLA 4804-1] libsmpp34 security update to fix one CVE in Bookworm related to an out of bound read.
  • [#1149107] trixie-pu of libsmpp34 has been created and wait for review by the release team.
  • [DLA 4805-1] mkvtoolnix security update to fix one CVE in Bookworm related to a heap buffer overflow.
  • [DLA 4806-1] pgextwlist security update to fix one CVE in Bookworm related to substituting extension schemas or owners matching [β€œ$’\].
  • [ELA-1837-1] mkvtoolnix gimp security update to fix one CVE in Bullseye to a heap buffer overflow.
  • [osmo-iuh] upload to fix a CVE related to a reachable assertion in Sid.

Besides doing these uploads, the month was filled with unscheduled meetings, discussions and explanations, all basically around the role of FD.

During my week of FD duties, I had to become familiar with new tools. As there are several things that FD has to do over and over again, I tried to automate this a bit. My experiments went well and I think this can be used to make FD duties less repetitive.

I also continued my work on cups and hplip and I am confident that I can do uploads in October. Last but not least I spend some time on security-master to assist others (especially the kernel team) with uploads to Bookworm and Bullseye.

In case you need to get a complete clone of the security-tracker, using the option –deepen n might be of help. Unfortunately in case you choosed n too high and some kind of error appears, something gets into a mess and you need to start almost from the beginning (some objects are still present and are used again). If you want to run a script, a value of 10 might be a good choice. You don’t have to deepen back to the beginning. At some point in time you can just –unshallow and get the whole rest. Afterwards doing a git gc is highly recommended.

Debian Printing

This month I uploaded a new upstream version or a bugfix version of:

  • … hplip to unstable, to fix an expired certificate and some bugs.

This work is generously funded by Freexian!

Debian Lomiri

Unfortunately this month my work did not make any progress.

Nevertheless, in case of any work done, this would have been generously funded by Fre(i)e Software GmbH!

Debian Astro

Unfortunately I had no time to work in this category this month.

Debian IoT

Unfortunately I had no time to work in this category this month.

Debian Mobcom

This month I uploaded a new upstream version or a bugfix version of:

misc

This month I uploaded a new upstream version or a bugfix version of:

  • … pkcs11-proxy to unstable to fix a bug related to openssl 4.0.
  • … meep to unstable to fix bugs.
  • … meep-mpi-default to unstable to fix bugs.
  • … harminv to unstable to fix bugs.
  • … libctl to unstable to fix bugs.
  •  

Dirk Eddelbuettel: myman 0.10.0 on CRAN: Three new waves of posts!

A new and exciting version of our still-new package myman reached CRAN this morning, and has been built for r2u and on r-universe. The matching Python package has also been updated. The package offers nineteen hundred eighty four β€œMy man …” posts by Kevin Kruse made on bsky during the summer of 2026. Each wave picked at one particular public persona. This package wrapse these up in the style of packages like fortunes or gaussfacts.

A sample usage illustration shows how to extract by pattern, and shows posts from the two most recent waves:

> library(myman)
> myman("maitre")
My man looks like he's inquiring with the maitre'd about the house curly fries.
     -- about Howard Lutnick on 2026-08-28

My man looks like a maitre'd who deeply doubts you have a reservation.
     -- about Scott Bessent on 2026-08-31

My man looks like he's asked the maitre'd to remove a party of four he finds visually
unpleasant.
     -- about Scott Bessent on 2026-08-31

My man looks like the maitre'd at a very exclusive restaurant called The Berghof.
     -- about JD Vance on 2026-09-13

My man looks like he's asking the maitre'd where they source their corn dogs.
         -- about Palmer Luckey on 2026-10-02

My man looks like Data had to borrow a sports jacket from the maitre'd.
         -- about Elon Musk on 2026-10-05
> 

One can also subset by β€˜target’, or sample randomly (which is the default).

As noted during the initial announcement last week, wave eight did not make it into the initial CRAN release as it happened while the package was under review. Waves nine and ten occured more or less while I was out of town last weekendβ€”so this release now brings three new waves to the CRAN package! We also added two new helper functions to extract the underlying data frame object, and tabulate the targetted men.

To align the version number with the count of post β€˜waves’, we switched to version 0.10.0 for this release and the corresponding Python package release so that both implementations now have the same version number.

The NEWS entry for this release follows.

Changes in version 0.10.0 (2026-10-08)

  • New waves nine (100 posts) and ten (190 posts) made last week; total is now 1984 posts

  • New helper functions posts() and men() retrieving data.frame of posts and tabulation of targets

  • Internal post gathering and aggregation functions have been updated and generalized

  • Versioning scheme now goes with post waves (also for Python sibbling)

Courtesy of my CRANberries, there is also a diffstat report for the most recent release. More information is available at the repository or the package page.

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. If you like this or other open-source work I do, you can sponsor me at GitHub.

  •  

Maytham Alsudany: Briefly looking at DNS and nameservers under the hood

I've always known that the browser uses the Domain Name Resolution (DNS) system to convert domain names like aezign.com.au into raw IP addresses, but have never actually understood how it works, outside of making sure my network config uses 1.1.1.1 or 8.8.8.8 instead of the crappy one the ISP provides. In this article, I set out to understand what nameservers do, and how they help anything that uses the internet find the right records.

DNS in a nutshell

A well-used analogy is a phonebook; when you have someone's name and need to find their phone number, you look through the phonebook. Overall, DNS does the same thing: when you enter an address like example.com, your browser will contact a DNS server (the "phonebook") to determine its IP addresses. On Linux (or MacOS) systems, you can use dig on the command line to perform a DNS lookup and see what this looks like:

$ dig example.com

; <<>> DiG 9.20.29-1-Debian <<>> example.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 42782
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;example.com.                   IN      A

;; ANSWER SECTION:
example.com.            221     IN      A       104.20.23.154
example.com.            221     IN      A       172.66.147.243

;; Query time: 20 msec
;; SERVER: 1.1.1.1#53(1.1.1.1) (UDP)
;; WHEN: Sun Sep 27 21:07:50 AWST 2026
;; MSG SIZE  rcvd: 72

Here, you can see the DNS server being used is 1.1.1.1 (Cloudflare's DNS server), and that it found the IPs 104.20.23.154 and 172.66.147.243 associated with the domain name example.com. Your browser will then contact these IP addresses directly to load the website you are trying to open.

Configuring DNS servers

You can configure DNS servers through your operating system's network settings, and for some applications such as Firefox, with the application itself. If you don't manually set a DNS server, your computer will use the ones provided by your modem. If those are not configured, the default defined by the modem manufacturer or your ISP will be used.

The most well-used and reliable DNS servers you can use are Cloudflare's (1.1.1.1 and 1.0.0.1) and Google's (8.8.8.8 and 8.8.4.4). Having more than one DNS server means that if the first one in the list doesn't work or doesn't find the matching IPs for a domain name, it will move to the next one in the list, a backup DNS server.

DNS servers must be configured as IP addresses. If your computer tried to use a DNS server at a domain name, then where would your computer find the IP address for that domain name? It wouldn't be able to, as this is the exact gap that DNS servers fulfill.

Records

DNS is not used only to find IPs for a domain, but a whole host of other things. Collectively they are referred to as "records" (or "DNS records"). Each record is associated to a domain (e.g. example.com) or a subdomain (e.g. bar.example.com, foo.bar.example.com) Here are some of the most common and important types:

  • A - Map to an IPv4 address (e.g. 104.20.23.154).

    This is the fundamental function of DNS: to map from a domain name to a server's IP address. Multiple A records leads to load balancing, where browsers will randomly select one of the returned IP addresses such that traffic is evenly split between them.

  • AAAA - Map to an IPv6 address (e.g. 2606:4700:10::6814:179a).

    This serves the same purpose as A records but for IPv6. Multiple AAAA records results in the same load balancing behaviour. All modern websites should have both an A record for legacy compatibility, and an AAAA record to future-proof for the gradual shift towards IPv6 addresses.

  • CNAME - Alias to another domain name (e.g. example.com).

    DNS servers will recursively lookup records for the aliased domain name until they reach an IP address (in an A or AAAA record).

  • MX - Specify a Mail Exchange server (e.g. mail.example.com).

    This record tells email SMTP servers where to direct emails to. For instance, the MX record for aezign.com.au is mail.aezign.au; this directs SMTP servers like Gmail and Outlook to send emails to the mailserver running at mail.aezign.au. This also allows specifying a priority field, so that you can define multiple MX records (such as a main and a backup) and consumers will try to connect to the listed mailservers from lowest priority to highest.

  • TXT - Store arbitrary text data

    This is most commonly used for site verification (for instance, to link your website to Google Search Console) and for email security measures like DKIM, DMARC, and SPF.

  • NS - Specify the nameservers for a domain (e.g. zeus.ns.cloudflare.com).

    These authoritative nameservers are responsible for providing all the other record types when needed.

dig lets you query each of these. For instance, to list the MX records against aezign.com.au:

$ dig MX aezign.com.au

; <<>> DiG 9.20.29-1-Debian <<>> MX aezign.com.au
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 28213
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;aezign.com.au.                 IN      MX

;; ANSWER SECTION:
aezign.com.au.          300     IN      MX      10 mail.aezign.au.

;; Query time: 104 msec
;; SERVER: 1.1.1.1#53(1.1.1.1) (UDP)
;; WHEN: Sun Sep 27 22:04:58 AWST 2026
;; MSG SIZE  rcvd: 70

Here you can see there is only one mailserver configured for aezign.com.au, which is mail.aezign.au, and it has a priority of 10.

If you compare this against something like gmail.com:

$ dig MX gmail.com

; <<>> DiG 9.20.29-1-Debian <<>> MX gmail.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 16538
;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;gmail.com.                     IN      MX

;; ANSWER SECTION:
gmail.com.              2497    IN      MX      40 alt4.gmail-smtp-in.l.google.com.
gmail.com.              2497    IN      MX      20 alt2.gmail-smtp-in.l.google.com.
gmail.com.              2497    IN      MX      5 gmail-smtp-in.l.google.com.
gmail.com.              2497    IN      MX      10 alt1.gmail-smtp-in.l.google.com.
gmail.com.              2497    IN      MX      30 alt3.gmail-smtp-in.l.google.com.

;; Query time: 120 msec
;; SERVER: 1.1.1.1#53(1.1.1.1) (UDP)
;; WHEN: Sun Sep 27 22:06:04 AWST 2026
;; MSG SIZE  rcvd: 161

You can see that gmail.com has several mailservers configured as redundancies due to the Gmail's sheer scale. gmail-smtp-in.l.google.com has the highest priority of 5, so SMTP servers will attempt to contact that mailserver first, followed by alt1.gmail-smtp-in.l.google.com and so on.

Nameservers

Now there needs to be somewhere for DNS records against a domain name to be defined, right? This is where nameservers come in.

Nameservers are DNS servers that answer queries about the domains they are authoritative for i.e. the domains they are in charge of. For example, the authoritative nameservers for example.com are hera.ns.cloudflare.com and elliott.ns.cloudflare.com, which means Cloudflare's nameservers are the source of truth when looking up DNS records for example.com. You can check this with dig:

$ dig NS example.com

; <<>> DiG 9.20.29-1-Debian <<>> NS example.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 37717
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;example.com.                   IN      NS

;; ANSWER SECTION:
example.com.            81837   IN      NS      hera.ns.cloudflare.com.
example.com.            81837   IN      NS      elliott.ns.cloudflare.com.

;; Query time: 140 msec
;; SERVER: 1.1.1.1#53(1.1.1.1) (UDP)
;; WHEN: Sun Sep 27 23:27:19 AWST 2026
;; MSG SIZE  rcvd: 95

Nameservers are configured with your domain name's registrar. The nameserver you set dictates where your remaining DNS records will live. For example.com, this means you would configure all your records on Cloudflare's dashboard, since they are responsible for the domain's DNS records.

Recursive resolution

The DNS servers that our computers use follow a recursive resolution process behind-the-scenes to find the authoritative nameservers for a domain, followed by the records you are querying.

Finding the root nameservers

Due to the recursive nature of the resolution process, there needs to be a starting point: the root (.) nameservers. The resolver uses a fixed list of root nameservers called root hints issued by IANA (named.root), to locate and contact the root nameservers. Resolvers will have this provided to them initially, and can dynamically update it themselves by querying one of the root nameservers for the root NS records to obtain a fresh list. For instance, we can query 198.41.0.4 (a.root-servers.net) to obtain a new list of root nameservers:

$ dig @198.41.0.4 NS .

; <<>> DiG 9.20.29-1-Debian <<>> @198.41.0.4 NS .
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 43677
;; flags: qr aa rd; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 27
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;.				IN	NS

;; ANSWER SECTION:
.			518400	IN	NS	l.root-servers.net.
.			518400	IN	NS	j.root-servers.net.
.			518400	IN	NS	f.root-servers.net.
.			518400	IN	NS	h.root-servers.net.
.			518400	IN	NS	d.root-servers.net.
.			518400	IN	NS	b.root-servers.net.
.			518400	IN	NS	k.root-servers.net.
.			518400	IN	NS	i.root-servers.net.
.			518400	IN	NS	m.root-servers.net.
.			518400	IN	NS	e.root-servers.net.
.			518400	IN	NS	g.root-servers.net.
.			518400	IN	NS	c.root-servers.net.
.			518400	IN	NS	a.root-servers.net.

;; ADDITIONAL SECTION:
l.root-servers.net.	518400	IN	A	199.7.83.42
l.root-servers.net.	518400	IN	AAAA	2001:500:9f::42
j.root-servers.net.	518400	IN	A	192.58.128.30
j.root-servers.net.	518400	IN	AAAA	2001:503:c27::2:30
f.root-servers.net.	518400	IN	A	192.5.5.241
f.root-servers.net.	518400	IN	AAAA	2001:500:2f::f
h.root-servers.net.	518400	IN	A	198.97.190.53
h.root-servers.net.	518400	IN	AAAA	2001:500:1::53
d.root-servers.net.	518400	IN	A	199.7.91.13
d.root-servers.net.	518400	IN	AAAA	2001:500:2d::d
b.root-servers.net.	518400	IN	A	170.247.170.2
b.root-servers.net.	518400	IN	AAAA	2801:1b8:10::b
k.root-servers.net.	518400	IN	A	193.0.14.129
k.root-servers.net.	518400	IN	AAAA	2001:7fd::1
i.root-servers.net.	518400	IN	A	192.36.148.17
i.root-servers.net.	518400	IN	AAAA	2001:7fe::53
m.root-servers.net.	518400	IN	A	202.12.27.33
m.root-servers.net.	518400	IN	AAAA	2001:dc3::35
e.root-servers.net.	518400	IN	A	192.203.230.10
e.root-servers.net.	518400	IN	AAAA	2001:500:a8::e
g.root-servers.net.	518400	IN	A	192.112.36.4
g.root-servers.net.	518400	IN	AAAA	2001:500:12::d0d
c.root-servers.net.	518400	IN	A	192.33.4.12
c.root-servers.net.	518400	IN	AAAA	2001:500:2::c
a.root-servers.net.	518400	IN	A	198.41.0.4
a.root-servers.net.	518400	IN	AAAA	2001:503:ba3e::2:30

;; Query time: 476 msec
;; SERVER: 198.41.0.4#53(198.41.0.4) (UDP)
;; WHEN: Mon Sep 28 00:01:08 AWST 2026
;; MSG SIZE  rcvd: 811

Querying the root nameservers

For example.com, the first step is to query the root (.) nameservers to find the nameservers for the .com top-level domain (TLD). Using a.root-servers.net again:

$ dig @198.41.0.4 NS com

; <<>> DiG 9.20.29-1-Debian <<>> @198.41.0.4 NS com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 22528
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 13, ADDITIONAL: 27
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;com.				IN	NS

;; AUTHORITY SECTION:
com.			172800	IN	NS	l.gtld-servers.net.
com.			172800	IN	NS	j.gtld-servers.net.
com.			172800	IN	NS	h.gtld-servers.net.
com.			172800	IN	NS	d.gtld-servers.net.
com.			172800	IN	NS	b.gtld-servers.net.
com.			172800	IN	NS	f.gtld-servers.net.
com.			172800	IN	NS	k.gtld-servers.net.
com.			172800	IN	NS	m.gtld-servers.net.
com.			172800	IN	NS	i.gtld-servers.net.
com.			172800	IN	NS	g.gtld-servers.net.
com.			172800	IN	NS	a.gtld-servers.net.
com.			172800	IN	NS	c.gtld-servers.net.
com.			172800	IN	NS	e.gtld-servers.net.

;; ADDITIONAL SECTION:
l.gtld-servers.net.	172800	IN	A	192.41.162.30
l.gtld-servers.net.	172800	IN	AAAA	2001:500:d937::30
j.gtld-servers.net.	172800	IN	A	192.48.79.30
j.gtld-servers.net.	172800	IN	AAAA	2001:502:7094::30
h.gtld-servers.net.	172800	IN	A	192.54.112.30
h.gtld-servers.net.	172800	IN	AAAA	2001:502:8cc::30
d.gtld-servers.net.	172800	IN	A	192.31.80.30
d.gtld-servers.net.	172800	IN	AAAA	2001:500:856e::30
b.gtld-servers.net.	172800	IN	A	192.33.14.30
b.gtld-servers.net.	172800	IN	AAAA	2001:503:231d::2:30
f.gtld-servers.net.	172800	IN	A	192.35.51.30
f.gtld-servers.net.	172800	IN	AAAA	2001:503:d414::30
k.gtld-servers.net.	172800	IN	A	192.52.178.30
k.gtld-servers.net.	172800	IN	AAAA	2001:503:d2d::30
m.gtld-servers.net.	172800	IN	A	192.55.83.30
m.gtld-servers.net.	172800	IN	AAAA	2001:501:b1f9::30
i.gtld-servers.net.	172800	IN	A	192.43.172.30
i.gtld-servers.net.	172800	IN	AAAA	2001:503:39c1::30
g.gtld-servers.net.	172800	IN	A	192.42.93.30
g.gtld-servers.net.	172800	IN	AAAA	2001:503:eea3::30
a.gtld-servers.net.	172800	IN	A	192.5.6.30
a.gtld-servers.net.	172800	IN	AAAA	2001:503:a83e::2:30
c.gtld-servers.net.	172800	IN	A	192.26.92.30
c.gtld-servers.net.	172800	IN	AAAA	2001:503:83eb::30
e.gtld-servers.net.	172800	IN	A	192.12.94.30
e.gtld-servers.net.	172800	IN	AAAA	2001:502:1ca1::30

;; Query time: 772 msec
;; SERVER: 198.41.0.4#53(198.41.0.4) (UDP)
;; WHEN: Mon Sep 28 00:09:25 AWST 2026
;; MSG SIZE  rcvd: 828

Querying the TLD nameservers

Now the resolver has .com nameservers and their IPs. We can use one of these, such as 192.5.6.30 (a.gtld-servers.net) to find the nameservers for example.com:

$ dig @192.5.6.30 NS example.com

; <<>> DiG 9.20.29-1-Debian <<>> @192.5.6.30 NS example.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 37419
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 2, ADDITIONAL: 13
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;example.com.                   IN      NS

;; AUTHORITY SECTION:
example.com.            172800  IN      NS      hera.ns.cloudflare.com.
example.com.            172800  IN      NS      elliott.ns.cloudflare.com.

;; ADDITIONAL SECTION:
hera.ns.cloudflare.com. 172800  IN      A       108.162.192.162
hera.ns.cloudflare.com. 172800  IN      A       172.64.32.162
hera.ns.cloudflare.com. 172800  IN      A       173.245.58.162
hera.ns.cloudflare.com. 172800  IN      AAAA    2606:4700:50::adf5:3aa2
hera.ns.cloudflare.com. 172800  IN      AAAA    2803:f800:50::6ca2:c0a2
hera.ns.cloudflare.com. 172800  IN      AAAA    2a06:98c1:50::ac40:20a2
elliott.ns.cloudflare.com. 172800 IN    A       108.162.195.228
elliott.ns.cloudflare.com. 172800 IN    A       162.159.44.228
elliott.ns.cloudflare.com. 172800 IN    A       172.64.35.228
elliott.ns.cloudflare.com. 172800 IN    AAAA    2606:4700:58::a29f:2ce4
elliott.ns.cloudflare.com. 172800 IN    AAAA    2803:f800:50::6ca2:c3e4
elliott.ns.cloudflare.com. 172800 IN    AAAA    2a06:98c1:50::ac40:23e4

;; Query time: 80 msec
;; SERVER: 192.5.6.30#53(192.5.6.30) (UDP)
;; WHEN: Mon Sep 28 00:12:19 AWST 2026
;; MSG SIZE  rcvd: 359

Finding the domain's nameserver

The response tells the resolver that the nameservers for example.com are hera.ns.cloudflare.com and elliott.ns.cloudflare.com. Now since these Cloudflare nameservers are also .com domains and Cloudflare is so commonly used, the .com nameserver provides optional sibling glue records as defined in RFC 9471 to prevent further roundtrips and optimize the process.

If we ignore the sibling glue records provided, the resolver would have to ask the .com nameservers for the nameservers for cloudflare.com:

$ dig @192.5.6.30 NS cloudflare.com

; <<>> DiG 9.20.29-1-Debian <<>> @192.5.6.30 NS cloudflare.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 40307
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 5, ADDITIONAL: 21
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;cloudflare.com.                        IN      NS

;; AUTHORITY SECTION:
cloudflare.com.         172800  IN      NS      ns3.cloudflare.com.
cloudflare.com.         172800  IN      NS      ns5.cloudflare.com.
cloudflare.com.         172800  IN      NS      ns4.cloudflare.com.
cloudflare.com.         172800  IN      NS      ns6.cloudflare.com.
cloudflare.com.         172800  IN      NS      ns7.cloudflare.com.

;; ADDITIONAL SECTION:
ns3.cloudflare.com.     172800  IN      A       162.159.0.33
ns3.cloudflare.com.     172800  IN      A       162.159.7.226
ns3.cloudflare.com.     172800  IN      AAAA    2400:cb00:2049:1::a29f:21
ns3.cloudflare.com.     172800  IN      AAAA    2400:cb00:2049:1::a29f:7e2
ns5.cloudflare.com.     172800  IN      A       162.159.2.9
ns5.cloudflare.com.     172800  IN      A       162.159.9.55
ns5.cloudflare.com.     172800  IN      AAAA    2400:cb00:2049:1::a29f:209
ns5.cloudflare.com.     172800  IN      AAAA    2400:cb00:2049:1::a29f:937
ns4.cloudflare.com.     172800  IN      A       162.159.1.33
ns4.cloudflare.com.     172800  IN      A       162.159.8.55
ns4.cloudflare.com.     172800  IN      AAAA    2400:cb00:2049:1::a29f:121
ns4.cloudflare.com.     172800  IN      AAAA    2400:cb00:2049:1::a29f:837
ns6.cloudflare.com.     172800  IN      A       162.159.3.11
ns6.cloudflare.com.     172800  IN      A       162.159.5.6
ns6.cloudflare.com.     172800  IN      AAAA    2400:cb00:2049:1::a29f:30b
ns6.cloudflare.com.     172800  IN      AAAA    2400:cb00:2049:1::a29f:506
ns7.cloudflare.com.     172800  IN      A       162.159.4.8
ns7.cloudflare.com.     172800  IN      A       162.159.6.6
ns7.cloudflare.com.     172800  IN      AAAA    2400:cb00:2049:1::a29f:408
ns7.cloudflare.com.     172800  IN      AAAA    2400:cb00:2049:1::a29f:606

;; Query time: 163 msec
;; SERVER: 192.5.6.30#53(192.5.6.30) (UDP)
;; WHEN: Mon Sep 28 00:26:53 AWST 2026
;; MSG SIZE  rcvd: 573

Here, the .com nameserver provides in-domain glue records for cloudflare.com's nameservers. Without these, there would be a circular dependency, since the nameserver named is a subdomain of the domain being queried for. This is because nameservers are always defined by name, which means that in order to actually contact the nameserver, your computer needs to obtain its IP address with another DNS lookup.

Next, we'd use one of these nameservers, say ns3.cloudflare.com, to obtain the IP for hera.ns.cloudflare.com:

$ dig @162.159.0.33 hera.ns.cloudflare.com

; <<>> DiG 9.20.29-1-Debian <<>> @162.159.0.33 hera.ns.cloudflare.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 16801
;; flags: qr aa rd; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;hera.ns.cloudflare.com.                IN      A

;; ANSWER SECTION:
hera.ns.cloudflare.com. 86353   IN      A       108.162.192.162
hera.ns.cloudflare.com. 86353   IN      A       173.245.58.162
hera.ns.cloudflare.com. 86353   IN      A       172.64.32.162

;; Query time: 123 msec
;; SERVER: 162.159.0.33#53(162.159.0.33) (UDP)
;; WHEN: Mon Sep 28 01:11:37 AWST 2026
;; MSG SIZE  rcvd: 99

Querying the domain's authoritative nameserver

Now we've reached the authoritative nameserver for example.com! The last thing to do is to fetch the A record for example.com to obtain its server's IP address:

$ dig @108.162.192.162 example.com

; <<>> DiG 9.20.29-1-Debian <<>> @108.162.192.162 example.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 43082
;; flags: qr aa rd; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;example.com.                   IN      A

;; ANSWER SECTION:
example.com.            300     IN      A       104.20.23.154
example.com.            300     IN      A       172.66.147.243

;; Query time: 123 msec
;; SERVER: 108.162.192.162#53(108.162.192.162) (UDP)
;; WHEN: Mon Sep 28 01:13:47 AWST 2026
;; MSG SIZE  rcvd: 72

At last, we've determined that the IP addresses of the servers behind example.com are 104.20.23.154 and 172.66.147.243. This matches our earlier lookup directly against your computer's configured DNS server.

The DNS servers your computer uses encapsulate this recursive resolution process behind the scenes, so that your computer only needs to make one round trip, and the servers can use their much faster data center connections and caching to optimize the process and make the query as fast as possible.

Checking DNS records

To check a website's records, the first thing to do is to ensure the domain name is pointed at the correct nameserver. For instance, aezign.com.au is supposed to use Cloudflare, since that is where all the DNS records have been set up. We can verify this using dig, (or alternatively with online tools like dnschecker.org):

$ dig NS aezign.com.au

; <<>> DiG 9.20.29-1-Debian <<>> NS aezign.com.au
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 44172
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;aezign.com.au.                 IN      NS

;; ANSWER SECTION:
aezign.com.au.          86400   IN      NS      rosalie.ns.cloudflare.com.
aezign.com.au.          86400   IN      NS      zeus.ns.cloudflare.com.

;; Query time: 92 msec
;; SERVER: 1.1.1.1#53(1.1.1.1) (UDP)
;; WHEN: Mon Sep 28 01:39:22 AWST 2026
;; MSG SIZE  rcvd: 100

If this is not set correctly, the DNS records you configure will not work, as resolvers will be fetching records from somewhere else. In most cases, you can update this in your domain registrar's settings. This is especially common for new domain names, which default to the registrar's nameservers; unless you plan to use their built-in DNS management, you'll need to point them to your chosen provider.

Now we can check that the DNS records configured match those your DNS server returns. For aezign.com.au, these are the MX and TXT records configured on Cloudflare.

Extract of Cloudflare's DNS record listing showing the MX record and TXT records for aezign.com.au.

The MX record and some TXT records configured for aezign.com.au on Cloudflare's dashboard.

We can check these using dig, and using the +short option to show only the content of the records.

$ dig MX aezign.com.au +short

10 mail.aezign.au.

$ dig TXT aezign.com.au +short

"google-site-verification=KFqTU5xH8fFf6OtszEL4oudfxple29Tm-TvxVtCWkAM"
"v=spf1 mx a:mail.aezign.au -all"

$ dig TXT _dmarc.aezign.com.au +short

"v=DMARC1;p=quarantine;sp=quarantine;adkim=r;aspf=r"

$ dig TXT aezign.com.au-2026._domainkey.aezign.com.au +short

"v=DKIM1; h=sha256; k=rsa; s=email; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAzL04yXZgB72YkoxS+tLK//aWx65TS4UA3F0qJ7el68SEuD4ehmg+61Ta9iS31H6U074dnjyoPDeaiGBa7ToTNCtiIts4/ghD/8nrENROE6hQAwRmTK18ODDHrRDW73hWe6Dg4cK5vmXi82/wWRZU9SDKbme28IE9uCVir3lCkKYLs1" "j16gR1Sjqr6a2+3o+EeVXnLJ4wXmJMm7KCIdn7zv0t9Z1eYcw672PdpYPAMpGb8uUsgaDBsNSpTcupPkz4SWj6TrOB80CPHjWseVY8EOJeRsNKQ/8LFoQEBl4Rxtb3HAmu4UIxSZ4QMVOLnXz67e85mA5XjcNIsVMzaWaowwIDAQAB"

As we can see, this matches, which means that the nameservers for aezign.com.au are correct and the DNS records are what we intend them to be.

Note that if you've recently changed the nameserver or DNS records for your domain, it can take anywhere between 10 seconds and 24 hours for the changes to take effect and propagate across the different DNS servers globally. Tools like dnschecker.org can check your records on different DNS servers worldwide to see if they're reflecting your changes. The reason for this is caching: DNS servers like 1.1.1.1 will cache results so it doesn't have to do the full resolution process every time, and uses the Time-To-Live (TTL) you configure in your DNS records as a guideline for caching duration.

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